Hand-held band saw

ABSTRACT

A powered hand-held band for cutting a work piece and a method for manufacture and use. The band saw includes alternate blade guides respectively for selectively using one of a first cutting path for cutting a work piece flush with respect to a work surface and a second cutting path for non-flush cuts.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Continuation of U.S. patent application Ser. No.12/122,207 filed on May 16, 2008 hereby incorporated by reference andthis application claims the benefit of Provisional Patent ApplicationSer. No. 60/930,502 filed on May 16, 2007.

FIELD OF THE INVENTION

This invention relates to a hand-held band saw for cutting work pieces,and more particularly a hand-held band saw and method for cutting a workpiece flush with a surface.

BACKGROUND

Vertical band saws are commonly used tools for cutting conduits, pipes,and a variety of other objects. However, vertical band saws are largeand difficult to transport. As a result, hand-held band saws weredeveloped for use on remote job sites by electricians, pipe fitters,carpenters and other trade persons.

Known hand-held band saws include a saw blade that circulates around twowheels coupled to a frame. The saw blade is guided along a path interiorto an outer surface of the frame parallel to the blade.

SUMMARY

The present invention provides a hand-held band saw capable of flushlycutting a work piece angularly extending from a work surface using aclosed loop saw blade circulatable about a blade travel path. In oneexample of the invention, the band saw includes a frame housing the sawblade and at least partially defining the blade travel path and acutting guide surface. A motor is connected to the frame and engagedwith the saw blade to circulate the saw blade along the blade travelpath. At least one first blade guide is connected to the frame forguiding the saw blade along a first cutting path portion of the bladetravel path, with the first cutting path providing for a substantiallyflush cut of the work piece with respect to the work surface.

In another example, a drive motor is connected to the frame. A drivepulley is rotatably connected to the motor and engaged with the blade.The drive pulley partially defines the blade travel path. At least onefirst blade guide is connected to the frame and positioned along theblade travel path adjacent the cutting guide surface. The first bladeguide defines a first blade cutting path portion of the blade travelpath, and the first cutting path provides for a substantially flush cutof the work piece with respect to the work surface.

In a third example, the saw includes a frame defining a substantiallyplanar cutting guide surface and a channel extending inwardly from aside of the frame including the cutting guide surface. A drive motor isconnected to the frame. A drive pulley is rotatably connected to themotor and engaged with the blade, and the drive pulley partially definesthe blade travel path. An idler pulley is rotatably connected to theframe on an opposing side of the channel from the drive pulley, and theidler pulley is engaged with the blade and partially defines the bladetravel path. A tension adjusting handle is attached to the frame andcoupled to the idler pulley for adjusting the tension of the blade. Ahandle is attached to the frame at an oblique angle adjacent thechannel. A first pair of blade guides is connected to the frame onopposing sides of the channel adjacent the cutting guide surface. Eachof the first pair of blade guides has a single, continuous blade guidingsurface, and the blade guiding surfaces jointly define a first bladecutting path portion of the blade travel path. The first blade cuttingpath is coplanar with the cutting guide surface of the frame. A secondpair of blade guides is connected to the frame on opposing sides of thechannel adjacent the first pair of blade guides. The second pair ofblade guides jointly defines a second blade cutting path portion of theblade travel path. The second blade cutting path is angled relative tothe first blade cutting path. The band saw blade is selectively engagedwith one of the first and second pairs of blade guides for being guidedalong one of the first and the second cutting blade paths for selectiveflush or non-flush cutting of the work piece with respect to the worksurface.

In one example of a method of manufacturing the hand held band saw, aframe is provided with a power source and a motor for rotating aclosed-loop saw blade. A first guide is connected to the frame providinga first cutting path for the blade which positions the blade so that aflush cut of a work piece with respect to a work surface, for example avertical wall or horizontal floor, can be achieved.

In one example of a method of using the hand held band saw, a band sawis provided with a first blade guide which positions the blade along afirst cutting path which is substantially planar to a cutting guidesurface defined by the frame and a work surface. A second blade guide isprovided for selectively positioning the blade along a second cuttingpath for non-flush cutting of a work piece with respect to the worksurface. On selection of the type of cut and either of the first or thesecond blade cutting paths, the band saw is positioned with respect tothe work surface such that the cutting guide surface rests on thesubstantially planar work surface thereby positioning the saw bladesubstantially planar with the work surface adjacent the work piece to becut. The saw motor is engaged and the blade is urged in contact with thework piece to cut the work piece substantially flush with the worksurface.

BRIEF DESCRIPTION OF THE DRAWINGS

The description herein makes reference to the accompanying drawingswherein like reference numerals refer to like parts throughout theseveral views, and wherein:

FIG. 1 is a partial perspective view of a known band saw positioned tocut a work piece projecting from a generally planar surface;

FIG. 2 is a perspective view of an example of the inventive hand-heldband saw having a saw blade positioned to make a flush cut;

FIG. 3 is a partial bottom view of the hand-held band saw of FIG. 2;

FIG. 4 is a partial and enlarged perspective view of one of the bladeguides of FIG. 2 without a saw blade for illustrative purposes;

FIG. 5 is a partial and enlarged bottom view of the hand-held band sawof FIG. 2; and

FIG. 6 is a partial perspective view of the hand-held band saw of FIG. 2positioned to flushly cut a work piece.

DETAILED DESCRIPTION

As illustrated in FIG. 1, known hand-held band saws 20 are typicallyconfigured and oriented to cut a work piece 10 projecting from a worksurface 12. A saw blade 22 is spaced apart from the work surface 12because of the position of the saw blade 22 relative to a frame 24 ofthe band saw 20. As shown, blade guides 26 on the known hand-held bandsaw 20 position the blade 22 above or inward of a guiding side 28 of theframe 24 used to abut the work surface 12. Since the blade 22 is inwardof and non-planar to the work surface 12, these known hand-held bandsaws 20 are not configured to effectively and efficiently cut the workpiece 10 flush with the work surface 12.

FIGS. 2-6 illustrate examples of a band saw 30 according to the presentinvention. Referring to FIG. 2, the band saw 30 includes a frame 40having a drive pulley deck 42, an idler pulley deck 48 generallycoplanar with the drive pulley deck 42, and a connecting portion 54connecting the drive pulley deck 42 to the idler pulley deck 48. Thedrive pulley deck 42 includes a motor side 46 visible in FIG. 2 and adrive pulley side 44 opposite the motor mounting side 46 as best seen inFIG. 3. The idler pulley deck 48 includes a tensioning handle side 52and an idler pulling side 50 opposite the tensioning handle side 52.

As shown in FIG. 2, a protective flange 56 depends substantiallynormally from the drive pulley deck 42 and the idler pulley deck 48.Preferably, the protective flange 56 extends around the outer perimeterof the drive pulley deck 42, the connecting portion 54, and the idlerpulley deck 48. The flange 56 can include a guide surface 57 to providestability when the band saw 30 is positioned against the work surface 12as shown in FIG. 6.

Referring to FIG. 2, the frame 40 defines a channel 58 between the drivepulley deck 42 and the idler pulley deck 48. The channel 58 extendsinwardly from a cutting side 41 of the frame toward the connectingportion 54, and the channel 58 extends between the drive pulley deck 42and the idler pulley deck 48. The channel 58 is dimensioned to acceptwork pieces 10 up to a predetermined size. Both the frame 40 and channel58 can be made larger or smaller to accommodate work pieces 10 ofvarious sizes.

FIG. 3 illustrates an example of the underside of the band saw 30. Adrive pulley 60 is rotatably coupled about a drive pulley axis 62 to thedrive pulley mounting side 44 of the drive pulley deck 42, and an idlerpulley 64 is rotatably coupled about an idler pulley axis 66 to theidler pulley mounting side 50 of the idler pulley deck 48. Asillustrated, the drive pulley axis 62 and the idler pulley axis 66 areparallel. However, the drive pulley 60 and idler pulley 64 canalternatively be mounted to the frame for rotation about obliquelyangled axes. In an alternative example, the frame 40 can include morepulleys (not shown) in addition to the drive pulley 60 and idler pulley64 depending on the configuration of the band saw 30.

Referring back to FIG. 2, a tension adjusting handle 68 is coupled tothe tensioning handle side 52 of the idler pulley deck 48. The tensionadjusting handle 68 can be used to adjust the position of the idlerpulley 64 by moving the idler pulley 64 in a direction transverse to theidler pulley axis 66. It is understood that the tension adjusting handle68 can be attached at another location on the band saw 30 to effectivelyincrease or decrease the tensions in the blade 86 as desired. It isfurther understood that a different mechanism can be used for adjustingthe position of the idler pulley 64 if desired.

A motor 70 is attached to the motor mounting side 46 of the drive pulleydeck 42. The motor 70 rotatably drives the drive pulley 60 around thedrive pulley axis 62. Alternatively, the motor 70 can be attached atanother location on the band saw 30 to drive the drive pulley 60 orotherwise rotate the blade 86. The motor 70 is driven by a battery pack(not shown) attached to the band saw 30 in electrical connection withthe motor 70. Other means for powering motor 70, for example an outletplug-in power cord, may be used.

A handle 72 is attached to the frame 40 adjacent the connecting portion54. The handle 72 is angled obliquely relative to the motor mountingside 46 of the drive pulley deck 42. Alternatively, the handle 72 can beattached to the frame 40 at another location and can be angled at adifferent angle than shown.

FIG. 3 illustrates a first pair of blade guides 74 a and 74 b attachedto the frame 40 on opposing sides of the channel 58. Each blade guide 74a and 74 b has an outer blade contact surface 74 c which defines a firstcutting path 78 between the blade guide contact surfaces 74 c. The firstcutting path 78 is parallel with the guide surface 57 of the flange 56.In a preferred example shown in FIGS. 3 and 6, the first cutting path issubstantially coplanar with the guide surface 57. Alternatively, theblade guides 74 a and 74 b can be positioned further outward away fromthe cutting side 41. In other words, the blade guides 74 a and 74 b canbe positioned such that the first cutting path 78 is substantiallyparallel, but not coplanar, with the guide surface 57. If the bladeguides 74 a and 74 b are positioned further outward, the cutting plane78 need not be coplanar with the surface 57 for the band saw 30 to becapable of making flush cuts.

FIG. 4 illustrates a close-up of the first blade guide 74 b on the idlerpulley 64 side of the channel 58. The blade guide 74 b includes a rollerbearing 76 rotatably coupled to the frame 40. The roller bearing 76rotates about a roller bearing axis 75 parallel to the drive pulley axis62. Alternatively, the blade guides 74 a and 74 b may be non-rotatableguiding surfaces, such as wear plates. Also, the roller bearing axis 75need not be parallel with the drive pulley axis 62, as the blade guides74 a and 74 b may be configured to twist the blade 86 as desired betweenthe drive pulley 60 and idler pulley 64 and the blade guides 74 a and 74b, respectively, if the axes 62 and 75 are obliquely angled. Further,blade guide 74 a can have the same structure as blade guide 74 b, or thetwo blade guides 74 a and 74 b can have different structures foreffectively guiding the blade 86 along the first cutting path 78.

Referring back to FIG. 3, the band saw 30 can also include a second pairof blade guides 80 a and 80 b similar to conventional blade guides 26 asillustrated in FIG. 1. Blade guides 80 a and 80 b are attached to theframe 40 on opposing sides of the channel 58. The blade guides 80 a and80 b define a second cutting path 84 (shown in phantom line in FIG. 5)positioned inward toward the frame 40 and obliquely angled to the firstcutting path 78. As shown in FIG. 4, in one example the blade guide 80 bincludes two roller guiding portions 82 a and 82 b, each of whichincludes a roller bearing 76. The guiding portions 82 a and 82 b arerotatably coupled to the frame 40 about parallel axes, and the portions82 a and 82 b are slightly spaced apart. Alternatively, the blade guides80 a and 80 b can consist of non-rotatable guiding surfaces, such aswear plates. Similarly, the blade guides 80 a and 80 b need not includetwo guiding portions 82 a and 82 b, though the use of two guidingportions 82 a and 82 b is preferred for retaining both sides of theblade 86 for guidance along the second cutting path 84.

In one example of a method of manufacture, operation and use, the blade86 is installed by moving the idler pulley 64 to a low-tension bladeposition using the tension adjusting handle 68. The blade 86 is thenpositioned around both the drive pulley 60 and the idler pulley 64 andengaged with either the first pair of blade guides 74 a and 74 b or thesecond pair of blade guides 80 a and 80 b. Then, the tension adjustinghandle 68 is used to move the idler pulley 64 to a higher tensionposition suitable for the selected guides 74 or 80 and cuttingapplication. Where a work piece 10, for example a pipe, I-beam, floorjoist or vertical pole, is desired to be cut flush to the work surface12, for example a vertical wall or a horizontal floor, the first guides74 a and 74 b would selectively be used. Where a flush cut is notnecessary or desired, the second guides 80 a and 80 b may selectively beused.

When a trigger 71 (shown in FIG. 1) is depressed, the battery or otherpower source provides electricity to the motor 70 causing the motor 70to rotate. The rotation of the motor 70 drives the drive pulley 60,which in turn causes the blade 86 to circulate along a blade travel path90 partially shown in FIG. 5 that encompasses both pulleys 60 and 64 andthe selected pair of blade guides 74 or 80, depending on the desiredcut. The blade travel path 90 includes the first cutting path 78 or thesecond cutting path 84 between the blade guides 74 or 80, respectively.The band saw 30 is positioned such that the channel 58 is aligned withthe work piece 10, then the band saw 30 or work piece 10 is moved suchthat the blade 86 contacts the work piece 10. In an alternate example,the frame cutting surface 57 is aligned and laid to rest on the worksurface to provide stability for the saw and the saw blade. As the blade86 cuts through the work piece 10, the cut portion of the work piece 10enters the channel 58. Relative movement of the band saw 30 with respectto work piece 10 continues until a desired amount of the work piece 10is cut.

To cut the work piece 10 at a position substantially flush with the worksurface 12, the blade is selectively engaged or positioned with thefirst pair of blade guides 74 a and 74 b and the band saw is oriented asshown in FIG. 6. Since the blade 86 is substantially coplanar with thesurface 57 of the frame 40, the blade 86 abuts the surface 12 when theframe 40 is positioned with the surface 57 abutting the generally planarsurface 12. Thus, when the blade 86 is engaged with the first pair ofblade guides 74 a and 74 b, the blade is substantially coplanar with thesurface 57 and the work surface 12 allowing for a flush cut of the workpiece 10 with respect to the work surface 12.

In alternate examples, the blade guides 74 a and 74 b can have alternatestructures from the above description. For example, instead of two setsof blade guides 74 and 80, blade guides 80 a and 80 b can be arrangedsuch that the guide portion 82 b of each blade guide 80 a and 80 b ispositioned to function as a blade guides 74 a or 74 b, with the blade 86movable from between the guide portions 82 a and 82 b for regular,non-flush cutting to being positioned on the outside of guide portions82 b for flush cutting. Similarly, instead of two sets of blade guides74 and 80, the blade guides 80 a and 80 b can have an adjustableposition, and the guide portions 82 a can be removable such that guideportions 82 b function as blade guides 74 a and 74 b. As anotherexample, blade guides 74 and 80 can be detachable from the frame 40,with one of the pairs of blade guides 74 or 80 attached at a timedepending on the desired cutting function.

While the invention has been described in connection with what ispresently considered to be the most practical and preferred embodiment,it is to be understood that the invention is not to be limited to thedisclosed embodiments but, on the contrary, is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the appended claims, which scope is to be accorded the broadestinterpretation so as to encompass all such modifications and equivalentstructures as is permitted under the law.

1. A powered hand-held band saw for use in cutting a work pieceangularly extending from a substantially planar work surface, the sawhaving a closed-loop saw blade circulatable about a blade travel path,the saw comprising: a frame housing the saw blade and at least partiallydefining the blade travel path and a cutting guide surface; a motorconnected to the frame and engaged with the saw blade to circulate thesaw blade along the blade travel path; and at least one first bladeguide connected to the frame for guiding the saw blade along a firstcutting path portion of the blade travel path, the first cutting pathproviding for a substantially flush cut of the work piece with respectto the work surface.
 2. The band saw of claim 1, wherein the firstcutting path is substantially planar to the frame cutting guide surface.3. The band saw of claim 1, wherein the first blade guide comprises apair of blade guides separated from each other along the first cuttingpath.
 4. The band saw of claim 3, wherein the frame defines a channelpositioned between the respective first blade guides along the firstcutting path.
 5. The band saw of claim 1, further comprising at leastone second blade guide connected to the frame for guiding the saw bladealong a second cutting path portion of the blade travel path, the secondcutting path positioned inward of the frame cutting guide surface withrespect to the first cutting path providing for a non-flush cut of thework piece with respect to the work surface.
 6. The band saw of claim 5,wherein the second blade guide comprises a pair of blade guidesseparated from each other along the second cutting path, the secondblade guides positioned so that the second cutting path is angularlydisplaced with respect to the first cutting path.
 7. The band saw ofclaim 5 wherein the saw blade is selectively positionable along one ofthe first and the second cutting blade paths for selective flush ornon-flush cutting of the work piece with respect to the work surface. 8.A powered hand-held band saw for use in cutting a work piece angularlyextending from a substantially planar work surface, the saw having aclosed-loop saw blade circulatable about a blade travel path, the sawcomprising: a frame defining a substantially planar cutting guidesurface; a drive motor connected to the frame; a drive pulley rotatablyconnected to the motor and engaged with the saw blade, the drive pulleypartially defining the blade travel path; at least one first blade guideconnected to the frame and positioned along the blade travel pathadjacent the cutting guide surface, the first blade guide defining afirst blade cutting path portion of the blade travel path, wherein thefirst cutting path providing for a substantially flush cut of the workpiece with respect to the work surface.
 9. The band saw of claim 8,wherein the first cutting path is substantially planar to the framecutting guide surface.
 10. The band saw of claim 8, wherein the firstblade guide comprises a pair of blade guides separated from each otheralong the first cutting path.
 11. The band saw of claim 10, wherein eachof the pair of blade guides includes a single, continuous blade guidingsurface.
 12. The band saw of claim 8 further comprising at least onesecond blade guide connected to the frame for guiding the saw bladealong a second cutting path positioned along the blade travel path, thesecond cutting path positioned inward in the frame with respect to thefirst cutting path providing for a non-flush cut of the work piece withrespect to the work surface.
 13. The band saw of claim 12, wherein thesecond blade guide comprises a pair of blade guides separated from eachother along the second cutting path, the second blade guides positionedso that the second cutting path is angularly displaced with respect tothe first cutting path.
 14. The band saw of claim 12, wherein the secondcutting path is inward of the first cutting path relative to the cuttingguide surface.
 15. The band saw of claim 12, wherein the saw blade isselectively positionable along one of the first and the second cuttingblade paths for selective flush or non-flush cutting of the work piecewith respect to the work surface.
 16. The band saw of claim 15, furthercomprising an idler pulley connected to the frame and engaged with thesaw blade; and wherein the blade travel path is defined by the drivepulley, the idler pulley, and one of the first blade guide and thesecond blade guide.
 17. The band saw of claim 16, wherein the framedefines a channel extending inward between the drive pulley and theidler pulley from a side of the frame including the cutting guidesurface; and wherein the first blade cutting path spans the channel. 18.(canceled)
 19. (canceled)
 20. (canceled)